We have cloned in E. coli sequences which are expressed in a mouse transplantable colon tumor. We have selected from these 7 clones which are expressed at a high level in the dimethyl hydrazine (DMH)-induced tumor but are essentially undetectable in the normal mouse colon, and 1 cloned sequence which is high in the normal colon but low in the tumor. The clones have also been screened with cDNA made with poly A+ RNA of normal liver and kidney. One sequence has been identified which is moderately to highly abundant in the tumor but absent from colon, liver and kidney. Othr sequences which show smaller changes have also been identified. This application focuses on these sequences. We propose to: rigorously quantitate the level of expression of each sequence in normal mouse colon, liver, and kidney, and the tumor; determine the tissue, tumor, and development specificity of expression of each sequence; determine the cell type which expresses each sequence in a variety of tissues, tumors, and developmental states; assess the expression of each sequence during the time course of DMH carcinogenesis on a single cell basis and also in mouse cell lines which have been transformed with DNA from a human colon tumor. Finally, full length and genomic clones of some sequences will be prepared and used to investigate whether expression is under transcriptional or post-transcriptional regulation, and whether regulation is reflected in chromatin structure, sequence methylation, or genomic sequence rearrangement or mutation. These data will, therefore, provide information regarding the molecular mechanisms of carcinogenesis.